Conformability, stability and element extrusion are main factors that affect packer sealing performance. Conformability is the ability of the seal to conform to the surface irregularity and imperfection on the casing inside diameter and mandrel outside diameter. Stability is the structural soundness of the seal assembly during set and the pressure above or below thereafter. Any sudden movement of the element during set and after set is considered structural instability, which negatively impacts seal performance. Element extrusion indicates that polymeric sealing material is acting like fluid during set and subsequent pressure above or below, which causes the sealing element to escape any available space or gaps.
Various seal designs are illustrated in U.S. Pat. No. 6,666,276; U.S. Pat. No. 8,490,979; U.S. Pat. No. 7,363,975 US2005/0230100; WO2010135644; US 2003/0080515; US2011/0147015 and U.S. Pat. No. 8,905,149. Lacking in these designs and addressed by the present invention are features such as radially stacked segments separated with a reinforcing member shaped to fold on itself as the seal is axially compressed when set. Seal rings that bookend the sealing element have outwardly facing ramps to guide out anti-extrusion rings with a conforming tapered surface for axial extrusion control. The stacked elements and the reinforcing member that separates them create a gap volume near the mandrel that enables fluid to escape rather than becoming trapped, which could undermine the sealing ability of the sealing assembly. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while appreciating that the full scope of the invention is to be determined from the appended claims.